Coal loading machine



Jan. 9, 1934. A. CQLLISQN I 1,943,235

COAL LOADING MACHINE Filed June 14, 1930 5 Sheets-Sheet 1 Jan. 9, 1934. T. A. COLLISON 3,943,235

COAL LOADING MACHINE Filed June 14, 1930 5 Sheets-Sheet 2 mum k Jan. 9, 1934. T. A. COLLISON 19943,?35

GOAL LOADING MACHINE Filed June 14, 1930 5 Sheets-Sheet 3 Patented Jan. 9, 1934 UNITED STATES PATENT OFFICE COAL LOADING MACHINE Application June 14, 1930. Serial No. 461,213

15 Claims.

This invention relates broadly to conveyer mechanism, more particularly to a new and improved machine for loading pit cars with coal or ore One of the objects of the invention is to provide a stronger and sturdier machine of this type than has hitherto been produced, and one composed of relatively fewer operative parts whereby the machine is cheaper to produce and more easily operated.

Another object of the invention is to produce a machine wherein such parts as are most subject to deterioration through use or exposure may be readily removed and replaced.

Another object of the invention is to provide a new and improved bed plate for the conveyer frame of the machine which is so constructed and mounted that it can be removed when worn and a fresh one substituted with the expenditure of a minimum amount of labor.

Another object of the invention is to provide new and improved guide shoes for the flightcarrying conveyer chain whereby the chance of parts freezing up, due to exposure of the parts to moisture, is greatly minimized.

Another object of the invention is to provide self-aligning guides or shoes for the conveyer chain at each end of the machine.

A further object of the invention is to provide new and improved guides for the conveyer chain at such points along the conveyer frame where the direction of travel of the chain is varied such that friction or wear upon the moving parts and upon the guides themselves is greatly minimized, whereby the machine may be operated with a minimum of expenditure of power.

A still further and more general object of the invention is to provide a machine of the type described that is simple in construction, easily operated and which may be utilized for the purpose intended with the exercise of a minimum amount of care and attention whereby the cost of operating labor is considerably reduced.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplifled in the construction hereinafter set forth, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings wherein I have illustrated a preferred form of embodiment of my invention,

Figure 1 is a side elevational view of the entire machine;

Figure 2 is an elevational view partly in section of the front part of the machine showing the guide shoes for the flight-carrying chains, showing in side elevation the construction of the forward end of the machine;

Figure 3 is a perspective schematic view showing the construction of the front and rear conveyer chain supporting mechanism;

Figure 4 is a detailed sectional view taken on the line 44 of Figure 5;

Figure 5 is an elevational view, partly broken away, taken on line 55 of Figure 4, showing the rear or discharge end of the conveyer frame and associated mechanism;

Figure 6 is a plan view of the bed plate;

Figure 7 is a side elevational view of the bed plate;

Figure 8 is a vertical sectional view taken through the front part of the machine, showing the nose and also the front guide shoe for the flight chain;

Figure 9 is a sectional view taken on the line 9-9 of Figure 1 showing a double track;

Figure 10 is an end elevational view of one of the flight bars;

Figure 11 is a similar View of the opposite end of one of the flight bars; I

Figure 12 is a view partly in section and partly in elevation of a portion of the rear end of the machine;

Figure 13 is.a sectional view taken on the line l3l3 of Figure 12;

Figure 14 is a sectional view taken on the line l414 of Figure 12.

Referring now to the drawings wherein similar reference characters refer to similar parts throughout the several views thereof, A denotes generally what I shall term the conveyer frame, having the loading end designated generally at B and the discharging end designated C. The conveyer frame A is supported as by means of the truck D, intermediate adjusting mechanism E, being interposed between the conveyer frame A and the truck D whereby the discharging end C of the machine may be raised or lowered by means hereinafter to be described.

The loading end B of the conveyer frame is adapted to rest upon the mine floor and to be projected under the coal pile so that the coal discharged thereon will be carried, by means hereinafter to be described, up the inclined portion 1 of the conveyer frame over the substantially horizontal part 2 of said frame, to be discharged from the rear end C of said conveyer frame into a pit car. Both the pit car F (not shown) and the wheels 3 of the truck D usually ride on temporary tracks laid on the floor of the mine.

Referring now to the conveyer frame the sides of said frame are formed by parallelly disposed steel members which extend substantially the entire length of the machine. These steel members are so formed by bending as to give the conveyer frame the side contour illustrated in Figure 1 of the drawings, that is to say, the horizontal part B at the loading end, the substantially horizontal part 2 at the loading end and the intermediate inclined part 1.

One set of the side members of the conveyer frame, just mentioned, comprise members formed of steel indicated at 4 and 5 respectively, preferably bent transversely into Z form. Each of these Z-shaped side members is provided with an inwardly extending plate 6, an outwardly extending plate '7 and an intermediate plate 8, said plates, of course, being integrally formed.

The reference numeral 9 denotes the bed plate of the machine, the same comprising an elongated rectangularly formed strip of steel which extends from end to end of the conveyer frame. This bed plate 9 as shown in Figures 6 and 7, is bent into the shape of the side members 4 and 5 of the conveyer frame. It is clamped between the faces of the side members in the manner hereinafter described.

The reference numerals l0 and 11 denote Z- shaped members which extend from end to end of the machine and have the outwardly extending plates 12, the inwardly extending plates 13 and the intermediate plates 14. The plates 12 of the Z-shaped members 10 and 11, respectively, rest upon the outer surface of the bed plate 9 adjacent to its outer edges directly above and in vertical alignement with the plates '7 of the Z- shaped members a and 5. The plates 7 of the Z- shaped members 4 and 5, the plates 12 of the Z-shaped members 10 and 11 and the bed plate 9 are pierced at spaced intervals, as indicated by the apertures 15 (Figure 6) to receive the shanks of a plurality of bolts 16 by means of which the assembly comprising the Z-shaped members 4 and 10 and the edge of the intermediately disposed bed plate on one side of the frame are securely clamped together and the corresponding Z-shaped members 5 and 11 and the opposite edge of the intermediately disposed bed plate 9 are likewise securely clamped together. Thus there is formed a rigid conveyer frame formed by the associated Z-shaped members and bed plate, the latter, as

described, being an integrally formed member extending from end to end of the machine. The plates 13 of the Z-shaped members 10 and 11, respectively, are provided with elongated, upwardly and outwardly extending flanges 1'7, which with the Z-shaped members 10 and 11 and the bed plate 9 form a trough which extends from end to end of the machine through which the coal to be loaded is conveyed from the loading end B of the conveyer frame to the discharging end C thereof. The flanges 17 of the Z-shaped members 10, 11, are braced at spaced intervals by suitably formed iron or steel braces 18, which are clamped to the assembly of Z-shaped members and bed plate by certain of the bolts 16 employed to clamp the members of the conveyer frame assembly together.

For convenience of construction, in the present instances, the flanges 12 of the Z-shaped members are broken at the point 19 but the individual members of both pairs of Z-shaped members are integrally formed and extend the entire length of the conveyer frame.

This angle iron or steel frame, it will be noted, provides a very strong and rugged structure. Moreover, the plates 13 of the Z-shaped side members and the bed plate 9 form housings for the conveyer chains as they move over the bed plate 9. Likewise the inwardly extending plates 6 of the Z-shaped members and 5 together with the bed plate 9, form housings for the conveyer chains as they pass downwardly beneath the bed plate.

Having thus described the construction of the conveyer frame, the manner of mounting the same adjustably on the truck D will now be described.

The reference numerals 18 and 19 designate angle iron side members of a supporting frame for the conveyer frame assembly. Similar angle iron members are provided as side members for the opposite side of this supporting frame. Securely riveted to the angle iron side members of the supporting frame at their upper ends and connecting the same, as shown in Figure 1, are the plates one of which is shown at 23. The plates 23 are flanged inwardly as at 26 and 2'7 and are securely bolted to the conveyer frame assembly as by means of certain of the bolts 16.

Thus it will be seen that the supporting frame, designated by the letter G is securely braced in every direction and at its upper end is rigidly attached to the Z-shaped angle iron members 4 and 5 on both sides of the conveyer frame assembly. In fact, this supporting frame has four points of rigid attachment with each of the Z-shaped angle iron members 4 and 5.

The side members 18 and 19 of the supporting frame G and likewise the side members upon the opposite side of this frame, are rigidly connected together as by means of the plates, 30 riveted as at 32 of said side members. The side members upon the opposite sides of the frame G are likewise suitably braced by cross members. Thus it will be seen that the lower ends of the four side members of the supporting frame G are securely braced and connected together, this supporting frame constituting a substantially rectangular open-sided and open-ended box which is braced in every direction.

Referring now to the truck construction indicated generally at D, the reference numeral 35 denotes one of two sills which extend longitudinally beneath the supporting frame G. These sills are preferably formed of L-shaped rolled steel. The sills 35 of the truck at their forward ends are apertured to receive the pivot members, one of which is shown at 39. Said pivot members extend through the ears 38, whereby there are formed bearings, such that a pivotal connection is established between the forward end of the sills 34 and 35 and both sides of the conveyer frame permitting of a relative rocking movement between the forward end of the truck and said conveyer frame.

It will be noted that the sills are underslung with respect to the axle of the wheels 3 of the truck and that the conveyer being pivotally mounted at the points 39 to said truck sills, the 1 that the loading end will have a bias to rest by gravity upon the mine floor.

The reference number denotes one of the wheels of an auxiliary truck so constructed and mounted that it can be swung downwardly when it is desired to move the machine from one place to another. A catch 86 normally holds this auxiliary truck in inoperative position.

Referring now to the construction of the forward end of the conveyer frame, the Z-shaped side members of the conveyer frame 4 and 5 and 10 and 11 at the point (Figure 2) on both sides of the frame are so formed that at this point they begin to diverge from each other to form substantially V-shaped spaces 96 at each side. In each of these V-shaped spaces is fitted a wedge shaped fillet, each fillet comprising preferably a steel forging which extends from the point 95 toward the front end of the frame.

Each of the wedge shaped fillets, indicated by the reference number 97, is securely bolted to the laterally extending flanges or plates 7 and 12 of the Z-shaped side members of the conveyer frame. In the present instance it will be noted that the bolts 98, 99, and 100 are passed entirely through the neighboring outwardly extending flanges or plates of the Z-shaped side members whereby said side members and the fillets 97 are most securely and firmly united, providing a substantially integral structure.

Each of the fillets 97 is provided with a rectangular aperture 101, said apertures being located directly opposite each other and extending through these apertures is a similarly shaped bar 102. This bar is nicely fitted into these apertures 101. Mounted upon this bar are the conveyer chain shoe members 108 and 104, said shoe members being comprised by steel forgings, are so mounted upon the bar 1 02 as to permit of a slight relative sliding movement taking place between them and the bar. Both of the shoe members 103 and 104 are provided with integrally formed, semi-elliptical raised tracks 103 and 104 The reference numeral 106 illustrates what may be termed the roller or conveyer chain shoe separator, said member comprising preferably a forged block of metal having a rearwardly extending flange 107 which rests upon the forward end of the conveyer-frame bed and is connected thereto as by means of the clamp plate 108 which is secured to said bed plate as by means of rivets or bolts. This roller chain shoe separator, it will be noted, is provided with a longitudinally extending aperture 112 whereby it is nicely fitted upon the bar 101.

Having thus described the manner in which the roller conveyer chain is carried and sup ported at the forward end of the machine, the manner in which it is supported upon the rear end of the machine will now be described.

The upper and lower Z-shaped frame members upon both sides of the conveyer frame diverge from each other near the rear end of the machine so as to form a space 113 between them at both sides of the conveyer frame. Extending transversally of the frame and between the ends of the Z-shaped side members thereof, is a bar 114. This bar is similar in construction to the bar 102 at the front end of the machine being rectangular in cross-section. Its opposite ends rest upon the laterally extending plates or flanges of the lower bars of the Z-shaped members of the conveyer frame. Mounted upon the bar 114 so as to have a slight relative sliding movement thereon are the roller chain shoe members 115 and 116, said shoe members being fitted nicely upon said bar and both having the raised integrally semi-elliptically formed tracks 117 and 118.

Securely bolted, as at 119, to the laterally extending flanges of both of the Z-shaped members at each side of the machine are brackets 120. Each of brackets 120 is provided with a longitudinally extending threaded bore adapted to receive the adjusting bolts 121. The outer ends 122 of the bolts 121 are received in recesses 123 formed in each end of the bar 114 and it will be seen that by rotating the bolts 121, bar 114 may be forced outwardly for a purpose hereinafter described to take up slack in the conveyer chains. Lock nuts 124 threaded upon the bolts 121 may be employed to prevent recessional movements of the bolts under the stress of the bar when the machine is in operation. Bar 114, it will be seen, carries the entire load imposed upon the conveyer chains in their work in moving the material upwardly over the conveyer bed.

Riveted to the bar 114, as at 125, is a plate or 100 table 126. This plate or table, it will be noted, extends underneath the rear end 126 of the bed plate 9 of the machine and has a forward and rearward sliding movement with respect thereto. This plate or table 126 provides a means for preventing the coal or other material being handled by the machine from falling through the conveyer frame. It also acts as a spacing member or separator for the roller chain shoe members and 116.

Having thus described the construction of the means employed at both ends of the machine for supporting and carrying the roller conveyer chains the construction of the latter will now be described.

Two of these chains are employed, one at each side of the machine and, as shown, each chain is endless and is located substantially between the inwardly extending flanges 6 and 13 of the Z-shaped side members of the conveyer frame, the lateral edges of the bed plate, of course, intervening. This construction is well illustrated in Figure 9 of the drawings. These conveyer chains are denoted generally by the reference 7 numbers 127 and 128. Each chain comprises a plurality of pivotally connected links, each link comprising two similarly formed side members 129 and 130 through which extend the pins or pivots which connect them and the neighboring i 0 links of the chain together. Mounted upon each 3 of the pivot pins is a roller 131, each roller comprising a cylindrically formed member of hardened steel positioned upon the pivot pins between the side members of the links as clearly illustrated in Figure 9 of the drawings.

Formed integrally with and extending laterally and inwardly from certain of the side mem bers of the links of the chain 128, are the studs 132, the arrangement being such that said studs are preferably spaced equally apart throughout the entire length of the conveyer chain.

Formed integrally and extending laterally and inwardly from certain of the side members of the links of the conveyer chain 127, are the rectangularly formed studs 133. The arrangement of these studs is also such that they are also spaced apart equally throughout the length of the conveyer chain, the inwardly extending studs, upon each of the chains, being disposed in lateral alignment.

The reference number 134 denotes the flights which are carried by the conveyer chain and traverse the bed plate longitudinally thereof to move the coal or other material being handled to the discharging end of the machine.

Each flight, it will be noted, comprises a bar which may be formed of cast steel or of iron or of a steel forging, is provided with a longitudinally extending recess 135 which is defined by the rims 136 and 137 which form a sort of pocket in which the protuberances of the material being conveyed may catch, whereby the flight is rendered more effective as an instrumentality to catch and convey the material being handled upwardly over the bed plate of the machine.

Each flight is provided at both ends thereof with recesses 13-3 and 139, said recesses being shaped so as to receive the inwardly extending studs formed upon the side members of the conveyer chain links as above described. The recesses 139 are preferably closed-sided and the recesses 138 of the flight are preferably opened at one side so that in assembling the flights upon the conveyer chain it is merely necessary to insert the stud 133 into the end of the recess 139 and then swing the flight into the position so that the studs 132 upon the opposite conveyer chain will be received in the recess 138. Rivets 149 are passed through the ends of the flights at the last described ends and through the studs 132 whereby the flights are securely fastened to the conveyer chains. It will be noted that in this construction a slight r -ative lateral movement between the conveyer chains is permitted.

As shown in th drawings these endless conveyer chains extend from end to end of the machine, said chains at the forward end of the machine riding over the raised tracks 103 and 104. of the shoes 103 and 104. At the rear end of the machine these conveyer chains ride over the raised tracks 117 and 118 of the shoes 115 and 116. The hardened steel of the rollers of the conve er chain, of course, directly engage with the raised tracks of the conveyer chain shoes and the side members of the chain links engage with the lateral sides of the tracks, a slight play being provided between these side walls of the tracks and the side links of the chains.

The reference numeral 1-621 denotes raised tracks or guides which are bolted or riveted to the inwardly extending flanges or plates of the Z-shaped side members and to the bed plate of the conveyer frame wherever there is a directional change in the travel of the conveyer chains during their course over or under the bed plate of the machine in raising the material being treated or in their return course from the rear of the machine to the forward end thereof. The rollers of the chains ride upon these tracks and the side members of the links straddle them so that these tracks or guides guide the chains in both a lateral and a vertical direction. As a matter of fact there are continuous tracks mounted upon the bed plate from end to end thereof. These tracks guide these conveyer chains in their upward movement over the bed plate.

Having thus described the construction of my improved pit car loading machine, the operation thereof is substantially as follows.

Assuming the machine to be in assembled condition, as above described, and the auxiliary truck in operation all of the coal that is deposited in front of the upwardly and forwardly moving conveyer flights will be carried upward and over the bed plate to be discharged from the rear end of the machine into a pit car which may be run under the rear end of the machine. Manual labor, of course, may be employed for shovel ing or otherwise lifting chunks of coal or ore upon the bed plate of the machine and in the trough provided by the bed plate, the plates 10 and 11 of the top Z-shaped members, and the upwardly and outwardly extending flanges of the latter, whereupon the flights will catch it and convey it over the bed of the machine to be discharged into the pit car.

As has already been mentioned in the mining of bituminous coal the market value increases with the size of the chunks delivered to the customer and the prime object of my improved machine is to provide an apparatus which will be sturdy and as nearly fool proof as possible whereby the discharge of the coal or ore from the mine floor into a pit car can be accomplished with as little chance as possible of the coal chunks breaking up.

The construction of the bed of the machine and its mounting upon the conveyer frame makes the matter of removing the bed for repair or replacement a very simple one. It is a well-known fact that in the operation of machines of this type the bed plates thereof soon deteriorate by reason of the friction of the material being handled sliding thereover and that it is necessary frequently to replace worn-out bed plates with fresh ones. This operation is very easily accomplished in my machine because the bed plate extends from end to end thereof and it may be removed and a new one substituted by a very simple operation.

It will be noted that the very thin edge given to the nose or header facilitate its being pushed under the coal pile. It will be further noted that in the machine, as described and claimed herein, the only parts moving when the machine is in operation are he conveyer chains, their rollers, and their flights as they pass over the bed. Thus there is no danger of the machine clogging up or being placed in inoperative condition due to the rusting caused by moisture to which machines of this type are exposed in mines. The mounting of the conveyer chain tracizs at each end of the machine is strong and rigid and the adjustment of said conveyer chains to take up slack therein is easily accomplished by a simple adjustment at the rear end of the machine.

The mounting of the conveyer chain shoes at both the front and rear end of the machine is also of such construction that said shoes will automatically adjust themselves to their proper positions so that there will be no binding on any part of the conveyor chains as they pass from end to end of the machine. This construction minimizes friction and diminishes the cost of operation of machines of this character.

It will also be noted that the removal of the nose piece or prow of the machine may be accomplished by merely removing the bolts 100 and 172.

It will be noted also that the thrust of the bination,

side sills of the truck is communicated to the conveyer frame near its front end so that no strain is imposed upon the parts of the conveyer frame and behind its points of pivotal connection with the sills when the latter are utilized in forcing the nose or prow under the coal pile. Moreover, the direction of thrust of the sills in performing this operation is parallel and almost in line with the plane of the nose or header.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

Having thus described my invention, what I claim as new and desire to secure by Letters Pat ent is:

l. A conveyer frame for loading machines comprising a pair of rigid side members at each side of the frame, a bed plate composed of a single metallic sheet extending the entire length of the frame, means for clamping the edges of said bed plate between the side members at each side of the frame, and a stationary tracked conveyer shoe mounted in the frame at each end of said bed plate.

2. A conveyer frame for loading machines comprising a pair of rigid side members at each side of the frame, a bed plate composed of a single metallic sheet extending the entire length of the frame, means for clamping the edges of said bed plate between the side members at each side of the frame, a stationary tracked conveyer shoe mounted in the frame at each end of said bed plate, and self-adjusting conveyer shoe members mounted upon each end of said frame.

3. A conveyer frame for loading machines comprising a pair of rigid side members at each side of the frame, a bed plate composed of a single metallic sheet extending the entire length of the frame, a conveyer shoe supporting bar mounted at each end of said frame, and conveyer chain shoes slideably mounted upon said bars.

4. In a machine of the class described, in combination, a conveyer frame having a bed plate, a bar extending through said conveyer frame at one end thereof, a pair of conveyer chain shoes slideably mounted upon said bar, and a spacer member for said shoes mounted upon said bar.

5. In a machine of the class described, in coma conveyer frame having a bed plate, a bar extending through said conveyer frame at one end thereof, a pair of conveyer chain shoes slideably mounted upon said bar, and a spacer member for said shoes mounted upon said bar attached to said bed plate.

6. In a machine of the class described, in combination, a conveyer frame having abed plate, a bar extending through said conveyer frame at one end thereof, a pair of conveyer chain shoes slide- 1 ably mounted upon said bar, a spacer member for said shoes mounted upon said bar, and means for clamping said spacer member to the end of said bed plate.

7. In a machine of the class described, in combination, a conveyer frame having a bed plate which extends from end to end of said frame, a pair of bars extending through said frame at each end thereof and located adjacent to the ends of the bed plate, a pair of conveyer shoes slideably mounted upon each of said bars, an endless conveyer chain traversing said shoes, and means for adjusting one of said bars whereby to produce or take up slack in said chain.

8. In a machine of the class described, in combination, a conveyer frame having a bed plate which extends from end to end thereof, a pair of bars extending transversally of said frame at each end thereof adjacent to the ends of the bed plate, a pair of tracked shoe members adjustably mounted upon each of said bars, a spacer for said shoe members mounted upon each of said bars, one of said spacer members being attached to one end of the bed plate, and means mounted upon the other of said bars extending beneath the bed plate.

9. In a machine of the class described, in combination, a conveyer frame having a bed plate which extends from end to end thereof, a conveyer chain supporting bar extending through said frame at each end thereof and located adjacent to the ends of said bed plate, a pair of conveyer shoes adjustably mounted upon said bar, a spacer member mounted upon each of said bars, one of said spacer members being clamped to the end of the bed plate and the other bar having a plate or table which extends under the bed plate, and means whereby said last named bar may be laterally adjusted with respect to said first named bar.

10. In a machine of the class described, in combination, a conveyer frame each side of which is formed by a pair of Z-shaped side members which extend from end to end of the frame, one of said Z-shaped members being provided with an upwardly and outwardly extending flange, a bed plate which extends from end to end of the frame between the members of each pair of said Z-shaped members, and means for clamping said bed plate between each pair of Z-shaped members.

11. In a machine of the class described, in combination, a conveyer frame the sides of which are formed by angle irons which extend from end to end of the frame and a bed plate which is clamped between said angle irons, the angle iron of each pair of side members diverging from each other at one end of the frame, a metallic fillet inserted in the space provided by the divergence of said angle irons, means for rigidly securing said fillets to said angle irons, and a conveyer chain shoe supporting bar extending through said fillets.

12. In a machine of the class described, in combination, a conveyer frame the sides of which are formed by angle irons which extend from end to end of the frame and a bed plate which is clamped between said angle irons, the angle iron of each pair of side members diverging from each other at one end of the frame, a metallic fillet inserted in the space provided by the divergence of said angle irons, means for rigidly securing said fillets to said angle irons, a conveyer chain shoe supporting bar extending through said fillets, a pair of conveyer shoes mounted upon said bar, and a spacing member for said shoes clamped to the end of the bed plate.

13. In a machine of the class described, in combination, a conveyer frame the sides of which are formed by angle irons which extend from end to end of the frame and a bed plate which is clamped between said angle irons, the angle iron of each pair of side members diverging from each other at one end of the frame, a metallic fillet inserted in the space provided by the divergence of said angle irons, means for rigidly securing said fillets to said angle irons, a conveyer chain shoe supporting bar extending through said fillets, a pair of conveyer shoes adjustably mounted upon said bar, and a spacing member for said shoes clamped to the end of the bed plate.

14. In a machine of the class described, in combination, a conveyer frame having side members and a unitary bed plate extending from end to end of the frame and clamped to said side members, a pair of conveyer chain shoes mounted in spaced relation at each end of said frame, each pair of said shoe members being arranged for self-adjustment in one direction, and means whereby the shoe members mounted upon one end of the frame may be adjusted to or from the pair of shoe members upon the other end of the frame.

15. In a machine of the class described, in combination, a conveyer frame having side members and a bed plate, a bar extending through said frame at each end thereof adjacent to the ends of the bed plate, a pair of tracked shoe members mounted upon each of said bars, the shoe members mounted upon each bar being self-adjusting in a lateral direction, the shoe members of one of said pairs being positively adjustable in a direction toward or away from the other pair of shoe members, and an endless roller chain traversing the tracks of said shoe members.

THOMAS A. COLLISON. 

